MOSgated devices are well known and commonly have the source and gate contacts on one side of a semiconductor die or chip, and the drain contact on the opposite side of the die. It is frequently desirable to have the drain and gate contacts on one side of the die and the source contact on the opposite side. Such devices are commonly termed “top drain” devices. U.S. Pat. No. 7,323,745, issued Jan. 29, 2008 entitled TOP DRAIN MOSFET in the name of Daniel M. Kinzer and assigned to the assignee of this application shows a top drain device and a process for its manufacture.
The process needed to manufacture the device of the above U.S. Pat. No. 7,323,745 is complex, leading to increased device cost and reduced die yield. It would be desirable to provide a top drain structure which can be more easily manufactured with a reduced number of mask steps and employing the same basic manufacturing process used for the conventional top source device having source and gate contacts on the same die surface.